Polyesters derived from 5-pentanolides

ABSTRACT

Polyesters are prepared by the condensation of 5-pentanolides (delta-valerolactones) in the presence of an alkaline reagent. These polyesters may be extended with polyisocyanates.

White Pfifl'it [191 Hayashi [451 Feb. 27, 11973 POLYESTERS DERIVED FROM 5- PENTANOLIDES [75] Inventor: Katsumi Hayashi, Mentor, Ohio [73] Assignee: The Luhrizol Wickliffe, Ohio [22] Filed: Feb. 22, 1971 [21] Appl. No.: 117,729

Related US. Application Data [63] Continuation-impart of Ser. No. 88,164, Nov. 9,

Corporation,

2,962,524 11/1960 Hostettler et a1 ..260/484 3,021,309 2/1962 Cox et a1. ..260/783 3,021,314 2/1962 Cox et al ..260/78.3

3,021,317 2/1962 Cox et al. ..260/78.3

3,477,998 11/1969 Nakahara et al. ..260/78.3

OTHER PUBLICATIONS Chem. Abstracts 53, 11234i (1959) Primary Examiner-William H. Short Assistant Examiner-13. A. Nielsen Attorney-Roger Y. K. Hsu, William H. Pittman, James W. Adams, Jr. and James V. Tura [5 7 ABSTRACT Polyesters are prepared by the condensation of 5 pentanolides (delta-valerolactones) in the presence of an alkaline reagent. These polyesters may be extended with polyisocyanates.

1 Claim, No Drawings POLYESTERS DERIVED FROM S-PENTANOLIDES This application is a continuation-in-part of copending application Ser. No. 88,164 filed Nov. 9, 1970.

This invention relates to new compositions of matter and methods for their preparation. More particularly, it relates to polyesters having repeating units of the formula wherein each of R and R is hydrogen or a hydrocarbon or substituted hydrocarbon radical and R is a hydrocarbon or substituted hydrocarbon radical.

The term hydrocarbon radical as used herein includes aliphatic, cycloaliphatic and aromatic (including aliphaticand cycloaliphatic-substituted aromatic and aromatic-substituted aliphatic and cycloaliphatic) radicals. It also includes cyclic radicals wherein the ring is completed through another portion of the molecule; that is, any two indicated substitutents may together form a cycloalkyl radical.

The following are illustrative of hydrocarbon radicals within the scope of this invention. Where a named radical has several isomeric forms (e.g., butyl), all such forms are included.

Many obvious variations of these radicals will be apparent to those skilled in the art and are included within the scope of the invention.

Substituted hydrocarbon, alkyl, aryl, etc., radicals are considered fully equivalent to the hydrocarbon, alkyl, aryl, etc., radicals and to be part of this invention. By substituted is meant radicals containing substituents which do not alter significantly the character or reactivity of the radical. Examples are:

Halide (fluoride, chloride, bromide, iodide) Hydroxy Ether (especially lower alkoxy) Keto Ester (especially lower carbalkoxy) Aminoacyl (amide Nitro C ano ioether Sulfonic acid ester Sulfonsmide The hydrocarbon or substituted hydrocarbon radicals represented by R, R and R in the compositions of this invention are usually free from ethylenic and acetylenic unsaturation and have no more than about 30 carbon atoms, desirably no more than about 12 carbon atoms. They are preferably lower hydrocarbon radicals, especially lower alkyl and aryl radicals, (most often alkyl), the word l0wer" denoting radicals containing up to seven carbon atoms. Still more preferably, at least one of R and R is hydrogen, the other is hydrogen or a lower alkyl radical and R is a lower alkyl radical, both lower alkyl radicals usually being methyl or ethyl.

The polyesters of this invention may be obtained by condensing, in the presence of an alkaline reagent, a 5- pentano-lide of the formula wherein R, R and R are as previously defined. These S-pentanolides (delta-valerolactones) are known in the art. A typical method for their preparation is disclosed and claimed in the aforementioned copending application Ser. No. 88,164, filed Nov. 9, 1970.

The condensation of the S-pentanolide is effected in an anhydrous medium in the presence of a small amount of the alkaline reagent which may be an alkyllithium, an alkali metal hydride, amide, alkoxide or the like. It is frequently convenient merely to mix the reactants and allow the exothermic reaction to proceed, although it may sometimes be advisable to use a relatively non-polar solvent such as ethyl ether, tetrahydrofuran, dioxane, ethylene or diethylene glycol dimethyl ether or the like. The reaction temperature is ordinarily between room temperature and about C.

The polyesters of this invention may be extended by reacting them with a diisocyanate of the formula- OCNZ-NCO, wherein Z is a divalent hydrocarbon or substituted hydrocarbon radical, preferably an aromatic or alkylaromatic radical. Typical diisocyanates which may be used are toluene diisocyanate, naphthalene diisocyanate and diphenylmethane diisocyanate.

Preparation and extension of the polyesters of this invention are illustrated by the following examples. All parts are by weight unless otherwise indicated. Specific viscosities are measured at 30 C. on a solution of 0.5

. gram of the compound in ml. of chloroform.

EXAMPLE 1 A mixture of M5 grams of 4,4-dimethyl-5-pentanolide and 6 ml. of a l.6 M solution of n-butyllithium in nhe-xane is shaken, whereupon an exothermic reaction occurs and the mixture solidifies. After standing overnight, the solid is dissolved in 700 ml. of chloroform and precipitated by pouring the chloroform solution into methanol. The precipitate is collected by filtration, washed with methanol and water, dried and precipitated again from chloroform by methanol. The resulting polyester has a specific viscosity in chloroform of 0.23.

EXAMPLE 2 A mixture of l grams of the polyester of Example 1 and 0.5 gram of diphenylmethane diisocyanate is heated in a nitrogen atmosphere to M C. at a pressure of 0.5 torr for 18 hours. There is obtained an isocyanate-extended polyester having a specific viscosity in chloroform of 0.57.

EXAMPLE 3 Following the procedure of Example 2, an isocyanate-extended polyester is prepared from l0 grams of the polyester of Example 1 and 0.2 gram of toluene diisocyanate. It has a specific viscosity of 0.68.

EXAMPLE 4 Following the procedure of Examples 1-3, a polyester is prepared from 2,4-dimethyl-5-pentanolide 

